question_answer 3)

                Verify that \[-(-x)=x\] for:                 (i) \[x=\frac{11}{15}\]                     (ii) \[x=-\frac{13}{17}\]

Answer:

                (i) \[x=\frac{11}{15}\] \[\text{LHS}\,=-(-x)\] \[=-\left( -\frac{11}{15} \right)\] \[=\frac{11}{15}\] \[=x\] = RHS                 (ii) \[x=-\frac{13}{17}\]                 \[\text{LHS}=-(-x)\] \[=-\left\{ -\left( \frac{-13}{17} \right) \right\}\] \[=-\frac{13}{17}\] \[=x\] = RHS